Who asked about the ISD17240?

I recently received an email from someone who is using a ISD17240 for special efects on a guitar. Unfortunately my email has taken to unexpectedly erasing some of my email while I am working with it. I may have to change my email proram. Please send me a new email and I'll try to NOT delete your email this time.

The person asked about syncing 2 messages without a drop out inbetween. Unfortunately, as far as I know there is no way to do that with the 17240. It may be that the folks at Nuvoton can answer this question but I can't. I don't remember the exact question the person had asked. It may be that one of the devices with a RAC pin can be set up to do what he wants but I'll have to better understand his question before I could accurately answer his question.

ChipCorder Programmer

I recently got an inquiry from a college student who is building a senior project using a ChipCorder where he wants to be able to play back roughly 70 individual short messages. The students project is to design a device that "talks" to the user. That is certainly one use that ChipCorders excel at, especially for a quick turn, relatively low volume application.

Unfortunately the one supplier of inexpensive programmers I was aware of no longer seems to be in business: Quadravox.

I asked my contacts at Nuvoton about this and they tell me that the Polish supplier, Marthel (http://www.marthel.pl/en/solutions.php#iprog) still makes programmers for all the ISD versions. I have sent off an email to the folks at Marthel to find out more information regarding their programmers. I'll deliver that info here once I get it.

Note: ChipCorder is a registered trademark of Nuvoton. This blog is an independent effort and in no way connected to Nuvoton.

ChipCorders with Lithium button cells

I recently had someone ask me about the use of a ChipCorder with a 3 volt lithium button cell. I have seen many applications that used 1 or 2 of these cells in series to power the device. A ChipCorder will work just fine with a lithium button cell (or 2 in series) , if you want to use those batteries. You should note however that the chemistry of those cells dictates a recovery time. That is, as you playback messages continuously, you will see the battery's internal resistance go up and the output will get distorted. If you then wait a view minutes and then play a message, it will again sound OK.

That is, a lithium cell is good for interment duty when driving a ChipCorder and not continuous duty.

Note: ChipCorder is a registered trademark of Nuvoton. This blog is an independent effort and in no way connected to Nuvoton.

ChipCorders - Which to Choose?

In my last post, I talked about the single message versions of the ChipCorders. All of them are fully self contained devices, just add pushbuttons, microphone and speaker the chip records or plays what ever is in its single memory. There are many applications, however that need multiple messages. There are a lot of ChipCorders to chose from. How do you pick which one to use? Here are a list of questions that will help you zero in on what you need.

1. Does your system already have a speaker driver and a microphone or line input?
Answer: If you already have those parts of your system, you don't need to reproduce them on the ChipCorder. The only "plain" analog memory are the ISD4000 series. These parts have what is essentially a Line-In and Line-out audio interface. They don't have a microphone pre-amp or a speaker driver. They are controlled by an SPI interface with an address resolution of 200 to 400 millseconds. I'll talk more on what that means later. There are 4 different size versions of this part with each having 4 different sample rate offerings. I'll try to explain that later also.

2. Do you have multiple audio inputs you want to mix into and/out of the ChipCorder's analog memory?
Answer: The swiss army knife of ChipCorders is the ISD5100 series. These devices have the same microphone interface as the rest of the ChipCorders but also have 2 other analog inputs, each with 4 different gain settings possible. They also have the standard ChipCorder speaker driver output but additionally have 2 other analog outputs possible. All of the inputs, outputs and analog memory can be configured almost any way, including mixed together. You can even use the on-board anti-aliasing filters in your application for other things beside record and playback.

And if that wasn't enough, all the early mentioned ChipCorders including the afore mentioned ISD4000 series had to be ordered with a fixed sample rate. In the ISD5100 series you can pick your sample rate via software on the fly. Which means you can record some of your messages at one sample rate and others at a different sample rate to maximize the efficiency of the storage area in the part. There are just 4 size versions of the ISD5100 series since you can control the sampe rate via software.

The ISD5100 series is controlled via a two wire I2C interface.

3. Do you need multiple messages but don't want the cost of a micro?
Answer: One of the latest ChipCorders is the ISD1900 series. These parts can be divided into 8 equal length messages where access to each message is controlled by a pin. Or in other words with the correct pin strapping you can build a system with 8 push buttons used to play or record up to 8 individual messages.

Another option is the ISD1700 series which has the best of both worlds (sort of). It has a simple (and a bit crude) multiple message capability. With the chips simple push button interface, you can stack messages in the chip's memory until you run out of space then you can erase the first or last messages and record more. Its sort of a circular memory.

This blog entry is long enough! If you have questions, add a comment to the blog and I'll answer them or get them answered.

Note: ChipCorder is a registered trademark of Nuvoton. This blog is an independent effort and in no way connected to Nuvoton.

ChipCorders - Where to go for Single Message

For those that need to redesign a project that used an old single message ChipCorder, you have several options. If you need to record and play for a relatively short time, your best bet is the ISD1600B or ISD1800 series products. These products give you simple access to a single message from 6 to 40 seconds according to the internal size of the memory and the sample rate of the device.

Each device has a single pin to control record and the option of 2 pins to initiate PLAY. One pin, PLAY EDGE (PLAYE) starts playback with a momentary pulsed level while the other pin PLAY LEVEL (PLAYL) plays the message as long as the level is held. The ISD1800 uses an active HIGH going pulse or level for record and play while and the ISD1600 uses an active LOW going pulse or level to control the part.

These devices include a simple microphone interface; just add the microphone plus 3 caps and 3 resistors and your done. The speaker is driven directly from 2 pins (don't ground either pin, you can let the smoke out).

I prefer the ISD1600B family because of (in my opinion) less distortion and background hiss and more speaker drive. The ISD1600B family may cost a little bit more but its worth it (again in my opinion). Additionally, the ISD1800 requires a 28 pin package while the ISD1600B uses a 16 pin package. Smaller is better.

I'll cover the multiple message options in a later Blog.

By the way, I don't work for Nuvoton, Winbond or ISD. I'm an independent consultant. I can be reached at joe@jarrett.com.

Note: ChipCorder is a registered trademark of Nuvoton. This blog is an independent effort and in no way connected to Nuvoton.

ChipCorders - Whats real, whats not

I have been searching around the web to see what other people are saying about ChipCorders. Unfortunately there is a lot of old data floating around regarding ChipCorders that are no longer available. For example, I found a site with a bunch of PDFs for down load with content I wrote for ISD in the early 1990s. This information is totally out of date and covers some products that haven't been available for 10 years.

Let me get one piece of data out immediately. All of the first generation ChipCorders, are gone. This list includes the ISD1000, ISD1016A, ISD1020A, ISD1420, ISD1416, ISD2560, ISD2590, ISD2575, ISD25120, and the ISD1110 . There are probably more like these I've forgotten about. All of these devices were built in non Winbond fabs and those processes haven't been viable for a number of years. You may find some stock in places, but don't do any new designs with these parts. That supply could disappear and there are no replacements.

If you come upon application data on any of these products, its pretty much worthless. None of the newer Nuvoton products are pin and function compatible with the older ones. If you need to respin a product that used one of these older devices, you will have to do some redesign to use the newer (and available) devices.

Helping with these redesigns is part of the reason I set up this Blog.

Note: ChipCorder is a registered trademark of Nuvoton. This blog is an independent effort and in no way connected to Nuvoton.

Starting a Kit Business

While I'm starting a blog and trying to get some consulting business based on ChipCorders, I think its also time to start a kit business. I have developed one kit that I'm about to productize and we will see where I go from there. You can find the Hill Country Kits blog at http://hillcountrykits.blogspot.com/.

And yes, I'm thinking about some ChipCorder kits. What would you like to see? Add a comment if you have ideas.

I own hillcountrykits.com by the way.

Note: ChipCorder is a registered trademark of Nuvoton. This blog is an independent effort and in no way connected to Nuvoton.